The loopback module is packaged in a standard MSA housing compatible with all QSFP/QSFP+ ports. Transmit data from the host is electrically routed, (internal to the loopback module), to the receive data outputs and back to the host. It provides an economical way to exercise QSFP/QSFP+ ports during R&D validation, production testing, and field testing.This loopback module provides QSFP/QSFP+ power Class 2, 3, 4 (standard), or 1,5,6 loading using a customer supplied +3.3V voltage supply.